1. Field of the Invention:
The present invention pertains to paper containers and, in particular, to paperboard or cardboard containers which are stored in a collapsed configuration.
2. Description of the Related Art:
Cartons made from paper products, such as paperboard and cardboard may be provided as a unitary sheet which has been formed by blanking and other operations by the carton manufacturer. Upon arrival to a consumer, a desired number of blanks can be erected, usually with one or more folding operations, using fasteners such as staples or adhesives as may be required. An advantage of such containers, in addition to their ease of shipment, is the reduced costs to a consumer since the consumer adds the value of erection.
However, some consumers prefer to use a partially fabricated container, one in which the carton manufacturer has applied one or more operations on a flat blank. For example, U.S. Pat. No. 2,396,168 and 2,676,750 disclose collapsible cartons in which a flat or planar blank is folded and certain portions thereof secured together with adhesive. These cartons are collapsed for storage and shipment to a consumer at a remote location. U.S. Pat. No. 3,525,466 is similar to the carton of U.S. Pat. No. 2,676,750 in that the carton blank is secured at the ends thereof with adhesive to form a tube. As a further example, U.S. Pat. No. 3,525,466 illustrates a six-sided tube, forming a container with six sidewalls and hexagonal endwalls, while U.S. Pat. No. 2,676,750 provides four sidewalls, producing a container with a rectangular cross-section.
Partially erected cartons can be shipped in a "flat" or collapsed tubular configuration with only a simple manipulation being required of a consumer to open the tube into a carton receptacle. Typically, a multiple section bottom is provided with adhesive securements among several sections so that the bottom can be unfolded and automatically positioned with simultaneous extension or opening of the sides of the carton. Further, this opening and erection of the carton can be accomplished in one continuous operation. Examples of such carton bottom constructions may be found in U.S. Pat. Nos.: 2,284,283; 2,327,709; 2,655,304; 2,741,399; 3,057,535; and 4,007,869. The cartons described in many of these patents provide a rapid and simple construction of an open top receptacle, but an automatically closing carton top has not been provided, and there has been a need in the art to provide this type of carton top construction, which can be automatically erected in a single, simple operation.
Further, it is desirable to also provide a secure locking of the carton top to prevent unintentional opening. For example, U.S. Pat. Nos. 1,150,489 and 3,058,585 disclose cartons having slotted top panels which interlock, but such constructions are not employed in automatically closing carton top arrangements.
U.S. Pat. Nos. 3,114,493 and 3,938,731, like many of the cartons referred to above, provide handles or hand holes aiding in the easy portability of the cartons, especially when filled with a relatively heavy product. U.S. Pat. No. 3,938,731, for example, provides a receptacle for use with a manual trash compactor, the compacted trash stored in the receptacle can at times be quite heavy, owing to the increased density resulting from compaction. In one embodiment, illustrated in FIGS. 15 and 16, a double thickness handle portion is provided upstanding from the closed carton top. The carton is however not of a locking type, and a strip of sealing tape is provided to maintain the carton top in a closed position, with the layers of the handles properly aligned to provide registration of the hand holes.